The invention relates to a method for avoiding safety-critical activation of a clutch in a hybrid module of a drivetrain of a motor vehicle, wherein the hybrid module is effective between the internal combustion engine and the transmission and has an electric drive, the clutch and a freewheel, and the clutch is used to start the internal combustion engine by transmitting a torque, supplied by the electric drive or the drivetrain, by a frictionally locking connection to the electric drive or the drivetrain or to decouple the internal combustion engine from the drivetrain for purely electric travel.
DE 10 2012 206 680 A1 discloses a hybrid module for a drivetrain of a vehicle. The hybrid module is arranged between the internal combustion engine and the transmission and has an electric drive, a clutch and a freewheel, wherein the clutch and the freewheel are each provided in parallel with one another in order to transmit torque from the internal combustion engine in the direction of the transmission. The freewheel transmits the torque from the internal combustion engine in the direction of the transmission and opens given a torque directed in the opposite direction, with the result that the vehicle can be driven optionally by the internal combustion engine or the electric drive or at the same time by both in combination. The clutch has thereby the tasks of starting the internal combustion engine by transmitting the torque supplied by the electric drive or the drivetrain, by connecting the internal combustion engine and the electric drive or the drivetrain in a frictionally locking fashion, or of decoupling the internal combustion engine from the drivetrain in order to operate the motor vehicle in a purely electrical fashion or in order to transmit the traction torque and thrust torque of the internal combustion engine in the hybrid travel mode.
Changing over from the electric travel mode to the hybrid travel mode therefore requires the clutch to be closed in order to start the internal combustion engine. In particular, in the case of starting or restarting using the kinetic energy of the rotating drivetrain, the closing of the clutch and the associated acceleration of the immobile internal combustion engine result in a corresponding torque which will be referred to below as interference torque. This interference torque can, under specific ambient influences, lead to safety-critical scenarios of the motor vehicle.